OK, I'll put myself out there...

I was aware of this, but the AI itself resulted in the sepia toning. I considered converting it to black and white, since I've had 4 or 5 B&W images accepted previously (which is not to say the image would otherwise have been accepted in light of the other issues pointed out). But then, weirdly enough, I was watching a recent Adobe Livestream about submitting AI images (what to do, what not to do, etc.). At one point, if I heard the presenter correctly, he suggested using Lightroom presets to give submissions a little boost to set them apart from other submissions. But this seemed entirely against Adobe Stock standards so I was a bit surprised. Ultimately, I think the subject will dictate what to do or what not to do with an image, particularly AI images, and I would rarely if ever take such advice. To me, the suffix "pre" means, "it's already been done--if not overdone--and should only be used for personal requirements and not stock photography.

Thanks, ABAMBO...I think you're right. Maybe they would have a couple issues slide, but collectivly I can see all of your points. I think I was relying on the strength of the concept itself rather than focusing enough on the technical issues.

And yes, with regard to a comment from another contributor elsewhere, I did provide the proper release. 

It was "Quality Issues." But I'm at the point where I think quality issues is the go-to selection when nothing else works as their reason for a rejection. Kind of like me selecting "Graphic Resource" when none of the other categories fit the subject. I probably went with "People" in this case, but is it really about people? Not really. The category could be "Time," Clocks, "Surrealism," but of course we don't have the luxury of chooseing from a list of very specific categories. Which is probably good if the overall scheme of things.